Euphausiacea

Belongs within: Eumalacostraca.

The Euphausiacea, krill, are reasonably sized (generally some centimetres long) pelagic, shrimp-like crustaceans. They are best known for their role in the marine ecosystem as food for larger animals, due to their habit of forming large swarms.

Characters (from Ax 2000): Carapace fused to first eight thoracomeres, forming cephalothorax (lateral folds of carapace covering only upper parts of gills); telson with long narrow subapical appendages on posterior third.

<==Euphausiacea
    |--BentheuphausiaB26 [BentheuphausiidaeMD01]
    |    `--B. amblyopsB26
    `--EuphausiidaeMD01
         |--ThysanoessaB70
         |    |--T. gregariaW81
         |    |--T. inermis (Kröyer 1846)W81, S00 (see below for synonymy)
         |    |--T. longicaudataB26
         |    |--T. longipesW81
         |    |--T. parvaB26
         |    `--T. raschiiB26
         |--NyctiphanesB70
         |    |--N. australisHR96
         |    |--N. couchiiB26
         |    `--N. norvegicaN00
         |--NematoscelisB70
         |    |--N. atlanticaB26
         |    |--N. difficilisB70
         |    |--N. megalopsB26
         |    |--N. micropsB26
         |    `--N. tenellaB26
         |--Tessarabrachion oculatusB70
         |--EuphausiaDAS03
         |    |--E. americanaB26
         |    |--E. brevisB26
         |    |--E. distinguinda Hansen 1911R02
         |    |--E. eximia Hansen 1911R02
         |    |--E. gibboides Ortman 1893R02
         |    |--E. hemigibbaB26
         |    |--E. krohniiB26
         |    |--E. lamelligera Hansen 1911R02
         |    |--E. lucensW81
         |    |--E. mucronata Sars 1883R02
         |    |--E. muticaB26
         |    |--E. pacificaCH97
         |    |--E. similisK-M02
         |    |--E. superba Dana 1852DAS03
         |    |--E. teneraB26
         |    `--E. vallentiniW81
         `--Rhoda Sim 1872 [incl. Boreophausia Sars 1883]S00
              `--R. jardineana Sim 1872 [incl. Boreophausia raschii]S00
Euphausiacea incertae sedis:
  Meganyctiphanes norvegicaBA04, W81
  ThysanopodaCH97
    |--T. acutifronsB26
    |--T. orientalisB26
    |--T. pectinataBH90
    `--T. tricuspidataCH97
  StylocheironCH97
    |--S. abbreviatumB26
    |--S. carinatumB26
    `--S. suhmiiCH97
  Pseudoeuphausia latifronsZS10

Thysanoessa inermis (Kröyer 1846)^{W81, S00} [=Thysanopoda inermis^S00, Boreophausia inermis^S00, Euphausia inermis^S00, Rhoda inermis^B26; incl. Thysanoessa neglecta^B26]

*Type species of generic name indicated

References

Ax, P. 1999. Das System der Metazoa II. Ein Lehrbuch der phylogenetischen Systematik. Gustav Fisher Verlag: Stuttgart (translated: 2000. Multicellular Animals: The phylogenetic system of the Metazoa Vol. 2. Springer: Berlin).

[BH90] Berra, T. M., & J. B. Hutchins. 1990. A specimen of megamouth shark, Megachasma pelagios (Megachasmidae) from Western Australia. Records of the Western Australian Museum 14 (4): 651–656.

[B26] Bigelow, H. B. 1926. Plankton of the offshore waters of the Gulf of Maine. Bulletin of the Bureau of Fisheries 40 (2): 1–509.

[B70] Briggs, J. C. 1970. A faunal history of the North Atlantic Ocean. Systematic Zoology 19 (1): 19–34.

[BA04] Bucklin, A., & L. D. Allen. 2004. MtDNA sequenceing from zooplankton after long-term preservation in buffered formalin. Molecular Phylogenetics and Evolution 30: 879–882.

[CH97] Castro, P., & M. E. Huber. 1997. Marine Biology 2^nd ed. WCB McGraw-Hill: Boston.

[DAS03] Dixon, C. J., S. T. Ahyong & F. R. Schram. 2003. A new hypothesis of decapod phylogeny. Crustaceana 76: 935–975.

[HR96] Heather, B. D., & H. A. Robertson. 1996. The Field Guide to the Birds of New Zealand. Viking: Auckland.

[K-M02] Klein-MacPhee, G. 2002. Jacks. Family Carangidae. In: Collette, B. B., & G. Klein-MacPhee (eds) Bigelow and Schroeder’s Fishes of the Gulf of Maine 3^rd ed. pp. 411–427. Smithsonian Institute Press: Washington.

[MD01] Martin, J. W., & G. E. Davis. 2001. An updated classification of the Recent Crustacea. Natural History Museum Los Angeles County, Science Series 39: 1–124.

[N00] Norman, A. M. 1900. British Amphipoda: families Pontoporeidae to Ampeliscidae. Annals and Magazine of Natural History, series 7, 5: 326–346.

[R02] Rampal, J. 2002. Biodiversité et biogéographie chez les Cavoliniidae (Mollusca, Gastropoda, Opisthobranchia, Euthecosomata). Régions faunistiques marines. Zoosystema 24 (2): 209–258.

[S00] Stebbing, T. R. R. 1900. Arctic Crustacea: Bruce collection. Annals and Magazine of Natural History, series 7, 5: 1–16.

[W81] Watson, L. 1981. Sea Guide to Whales of the World. Hutchinson: London.

[ZS10] Zhang, G.-T., S. Sun, Z.-L. Xu & Q.-L. Zhang. 2010. Unexpected dominance of the subtropical copepod Temora turbinata in the temperate Changjiang River estuary and its possible causes. In: China-Russia Bilateral Symposium: Proceedings of the China-Russia Bilateral Symposium of “Comparison on Marine Biodiversity in the Northwest Pacific Ocean”, 10–11 October 2010, Qingdao (China) pp. 100–102. Institute of Oceanology, Chinese Academy of Sciences; A. V. Zhirmunsky Institute of Marine Biology, Far East Branch of the Russian Academy of Sciences.